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Synthesis of Pyrazoles Utilizing the Ambiphilic Reactivity of Hydrazones

Haruo Matsuzaki, Norihiko Takeda, Motohiro Yasui, Yuta Ito, Keiji Konishi and Masafumi Ueda*

*Kobe Pharmaceutical University, Motoyamakita, Higashinada, Kobe 658-8558, Japan, Email:

H. Matsuzaki, N. Takeda, M. Yasui, Y. Ito, K. Konishi, M. Ueda, Org. Lett., 2020, 22, 9249-9252.

DOI: 10.1021/acs.orglett.0c03465

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The ambiphilic reactivity of hydrazones enables not only self-condensation but also cross-condensation, affording multisubstituted pyrazoles in high yields, with a broad substrate scope. This convenient Brønsted acid-mediated reaction proceeds under mild conditions via a β-protonation/nucleophilic addition/cyclization/aromatization sequence.

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Key Words


ID: J54-Y2020